PT2221158E - Process and apparatus for treatment of a material - Google Patents

Description

1

A PROCESS AND DEVICE FOR THE TREATMENT OF A MATERIAL " The invention relates to a process according to Claim 1, as well as to a device according to Claim 5.

Numerous uses of the recycling of plastic materials suffer under the influence of problematic loading influences such as high residue moisture, large density variations, provision of too large portions etc. Due to this the performance of the next extruder is influenced negatively, or the economy of the process. The extruder suffers from these loading influences because they lead to a reduced or variable ejection power, an irregular melt potency, a reduction in the quality of the product, possibly to a greater wear and a reduction in productivity.

From the state of the art, for example from WO 00/74912 A1, devices with two mixing tools placed one above the other on the compactor cutter are known, which reduce such problems. The zone, where the grinding or drying or heating of the material predominates, is separated from the area where the material is compressed in the housing of the helical worm conveyor. Therefore a balance is established after a short service period between the volume of material ejected by the helical worm conveyor below the impeller disc and the stream of material which penetrates from the top through the slit in the space below the drive disc. This has the consequence that the space below the impeller disc, essentially filled with the material transported through the helical worm conveyor, which circulates in the form of a mixing swirl in the collecting vessel, undergoes a certain contrary resistance that in general only an increasingly smaller part of the new material introduced into the collecting vessel also reaches the area below the rotating drive disc. This has the consequence that the space located below the impeller disc, essentially filled with the material conveyed by the helical worm conveyor circulating in the form of a mixing swirl in the collecting vessel, offers a certain resistance to the discharge of the material , so that, in general, only a small minimum amount of the new material introduced into the collecting vessel can also reach below the area below the rotating drive disc.

This brings with it the guarantee of a sufficient residence time of the material in the collecting container, particularly in the area thereof which lies above the impeller disc. By this the temperature of the material introduced by the loading aperture in the collecting vessel is uniformized since essentially all the particles of plastic material in the vessel are sufficiently pre-treated. The approximately constant temperature of the material entering the housing of the helical worm conveyor results in the continually eliminating cores or non-homogeneous zones from the worm conveyor housing and thus the length of the helical worm conveyor 3 can be maintained smaller than in known constructions, since the worm conveyor has to perform less work to sequentially carry the plastic material at a uniform plastification temperature. The constant inlet temperature of the plastic material in the housing of the helical worm conveyor also has the effect of uniform prior compaction of the material in the housing of the helical worm conveyor, which acts favorably on the behavior in the extrusion aperture, especially in the form of a uniform extrusion product and a quality of material uniform to the outlet of the extruder. In comparison to other constructions, the shorter length of the worm conveyor produces energy savings and a lower temperature in the extruder since in fact the average temperature at which the material enters the housing of the worm conveyor is more uniform than in these other constructions. In this type of devices it is therefore necessary that the material to be treated, considered throughout the treatment process, be brought to a lower temperature when compared to the known constructions, in order to be sure to obtain sufficient plastification. This reduction in peak temperatures results in the aforesaid energy saving and further avoidance of thermal deterioration of the material to be treated.

By means of the arrangement of two mixing tools, installed one above the other, in the cutter and the construction of two successive treatment steps, a simple way of obtaining a separation of the work steps from " material treatment, i.e. grinding, drying, preheating, compaction and mixing, of the steps of " loading the extruder ". By means of the separation between both work steps are maintained sufficiently far removed from the extruder and its more sensitive areas of loading and introduction as described above, negative influences of the loading process. The result is an extruder fed very evenly and with a more uniform operation, which, irrespective of the influences of the loading process can constantly apply up to 15% more energy. Larger portions of the supply can also be treated, higher residue moisture is allowed in the product supplied, a higher throughput can be achieved, the material has a lower melting temperature and energy savings are obtained, with a higher quality of the granulate.

This type of device has proved to be very suitable for the treatment of plastic materials, especially thermoplastics, but it has been found that, among other things, more volatile substances leaving the material to be treated are kept in the space bottom of the upper drive disc. These volatile substances can not always expand upwardly through the annular gap formed between the impeller disc edge and the inner wall of the collecting vessel, in particular because in fact, through the annular slit, the material to be treated penetrates from top to bottom . Particularly unpleasant is when the volatile substances are transported together with the treated material out of the collecting vessel and arrive directly or indirectly at the extruder connected to the collecting vessel, because then there is the danger that in the extruded material they are created gas bags of different types, which essentially impairs the quality of the material obtained at the outlet of the extruder. This danger can also not be completely avoided by means of a degassing device generally provided in the extruder. Moreover, such undesirable volatile substances or substances can generally not be avoided in advance because they are water vapor, products of separation of the material to be treated, particles of cooling medium in the form of gas or vaporized etc. Especially if the content of these volatile substances is introduced into the collecting vessel by wet plastic material because it is considerable. In order to reduce such disadvantages and to make the material leaving the outlet opening of the collecting container at least essentially free of said volatile substances with little expense, it may be provided that the impeller disc has at least one perforation, particularly installed near the axis and near the rear edge of the tool, in the direction of rotation of the impeller disc, which connects the empty space above it to the empty space beneath it. Through this perforation, the volatile substances which lie in the void space below the impeller disc or there originate, expand through the impeller disc into the void above it, where they are not damaging and from which they may eventually escape. In this case it has been found through research that perforations located near the shaft have a more effective action than perforations placed away from the shaft. The perforations placed near the trailing edge of the tool relative to the rotation of the impeller disc use the suction action produced by the rotating tool 6 in order to draw the said volatile substances out of the space under the impeller disc.

Nevertheless, such devices are generally not capable of completely expelling undesired substances without leaving residues, which results in a deleterious influence on the preparation or treatment.

As undesirable substances, all substances which derive from the material to be treated or are released from the introduced material or which are eventually introduced with the material and which may carry with them a deleterious influence on the treatment . The unwanted harmful substances may adhere externally to the surfaces of the material to be treated, such as wash water, surface coatings etc. and then evaporate, or sublimate thereto, release from the outer surface or the like. The undesired substances may however be present in the matrix of the material or within the material and then, following the treatment, diffuse outwards and therein evaporate, sublime or the like. This may be observed especially with complementary organic materials, for example plasticizers, but also water, monomers, gases or waxes may be present in the matrix. Substances that have to be removed may also be sublimated solids or dust. The problem is particularly encountered with plastics materials with a high external humidity, such as for example polyolefin wax shavings etc. Also materials with higher internal moisture, for example PA (polyamide) fibers 7, are problematic. Between the impeller disks or the mixing tools can therefore arise, for example through the air saturated with moisture, condensation and vaporization, which also, in addition to the other mentioned drawbacks, leads to a greater need of energy from the part of the system.

Devices are known from the state of the art, with which, by means of suction devices, the water vapor which has been created on the material to be treated can be sucked. However, it is hardly possible for a collecting vessel, as used in the above-mentioned devices, to be essentially impermeable to the gases in its lower zone or to have a stream of air coming from below to compensate for the pressure, so that air saturated with moisture can not be well aspirated. In devices with multiple disks or mixing tools installed one above the other, this is linked to additional difficulties.

In the preparation of material with high residual humidity, due to the resulting large amounts of water vapor, a certain dynamics of movement is observed in the cutter, which supports a suction of the humid air. However, this is not the case in the treatment of material with low residual moisture, by mixing the saturated air of moisture in a central outlet of the mixing swirl immediately above the level of the material. A support dynamic is not formed and the aspiration or removal of this moist air is essentially more difficult. 8

According to DE-A-2609850, a process according to the preamble of Claim 1 or a device according to the preamble of Claim 5 is known from the state of the art. The object of the present invention is therefore to create a process or a device through which it is possible to remove undesirable harmful substances from the material which adversely affect the treatment or the subsequent finishing of the material, for example volatile substances, in particular moisture or water vapor, and influence and preparation in an advantageous manner.

This object is achieved by a process according to the prior art, by the defining features of Claim 1 and a device according to the prior art, by the defining features of Claim 5.

For this purpose it is provided in the process according to the invention that the gas is introduced into the vessel by means of gas introducing means, which are arranged or are constructed in at least one mixing tool and / or a propeller disc which supports the mixing tool.

In the device according to the invention it is provided that the gas introduction means is arranged or constructed in at least one mixing tool and / or drive disc.

By the arrangement of the gas introducing means according to the invention an advantageous current 9 can be created through at least a partial zone of the material, whereby the moisture or undesired substances are effectively expelled.

Further advantageous embodiments of the invention are described in the Subordinate Claims.

The gas introducing means may be constructed as passive means for introducing the gas, for example as simple passage openings, through which the gas enters passively, for example sucked only by the depression created inside the cutter-compactor. The gas introducing means can, however, also be performed as active means for introducing the gas, for example in the form of nozzles or the like, through which the gas is actively introduced into the overpressure cutter by means of blowing, spraying or pumping, produced by pumps, fans etc.

Likewise, the gas introducing means can be constructed as passive inlet means, through which the gas is only forced or penetrates into the collecting vessel due to the overpressure, or as active means of introducing the gas, for example driven through of suction pumps.

Advantageously the gas is, before being introduced into the collecting vessel, heated or dried by means of a heating device or a gas drying device, which is arranged upstream. In this way the withdrawal of undesired substances or also the control of the process can be effectively conducted. 10

For regulating the introduction or withdrawal of the gas, the gas inlet and / or outlet means are at least partially lockable or controllable.

The gas introducing means may be constructed as separate individual apertures, which have a diameter between 10 and 300 mm, preferably between 50 and 90 mm.

On the side facing the interior of the collecting vessel, the gas introducing means, especially above the direction of rotation of the material, a cover or a protection can be provided to prevent the material from clogging the gas introduction means. In order to, as best as possible, not disturb the rotational movement within the collecting vessel and prevent local overheating, it is further advantageous that the gas introduction means terminate at the level of the inner wall of the collecting vessel and does not project or move beyond it. The characteristic construction of the gas introducing means as well as its position have influence on the flow of the material stream by the gas and thus on the expulsion of the undesired substances.

The gas introducing means may further be constructed on the bottom surface of the cutter-compactor below the lower lower mixing tool and therein, preferably within the innermost third of the radius of the bottom surface. When the gas introducing means is constructed on the bottom surface, there is also a cleaning of the sediment by venting the gases from below, whereby even better material preparation is ensured.

The gas introducing means may for this be constructed as separate single apertures or in the form of a nearly perforating, annular slit-shaped aperture around the perforation of the drive shaft of the mixing tool through the bottom surface .

Alternatively or in addition to the aperture in the bottom surface, the gas introducing means may also be located in the side wall of the cutter-compactor, whereby to ensure that the gas introduction means is permanently below the level of the material . Advantageous positions of the gas introducing means located in the middle of the lower third of the total height of the cutter-compactor, especially below the lower mixing tool, or installed closer to the bottom.

In devices with various mixing tools installed one above the other it is extremely advantageous for the execution of the process that the gas introducing means is placed between the mixing tools located higher up and down or emerging into the space created therebetween. In this way the material is well traversed by gas or air and the chain acts in collaboration with the mixing operation by means of the mixing tool.

Advantageously, the gas introducing means does not flow into the edge region of the impeller disks or the mixing tools, but rather each ends or is arranged particularly in the zone between each two impeller disks or mixing tools in the collecting vessel for the that the gas introduction means is disposed, preferably in the middle, between each two impeller disks or mixing tools.

In this context it is especially advantageous that perforations are constructed on the above installed impeller disc, since in that way the undesired substances can be effectively removed from the area between the mixing tools.

When the gas introducing means is constructed in any zone of the side wall of the container in which the particles of rotating material exert the greatest pressure, it is necessary that said gas introduction means counteract the action of said pressure and that pressure gas into the vessel as active means for introducing gas.

Also in the side wall, the gas introducing means can be constructed as separate unit openings. However, they may also be constructed in the form of an annular groove, which extends along the periphery.

According to a preferred embodiment it is advantageous that, on the lower side of the drive discs, impeller flaps are constructed, which produce a flow of material and gas upwards from the area below the impeller disks. In this embodiment the impeller flaps advantageously act in conjunction with the gas introducing means and optionally with built-in perforations and thus ensure an efficient transport of the material out of the zone below the impeller disks and an advantageous development of the process. In order to prevent entrainment of particles or fragments of material due to too strong aspiration of the gas, it is advantageous that the gas withdrawal means is located as far away as possible from the level of the material, in particular the lid of the collecting vessel.

Other features and advantages of the invention are drawn from the description of examples of embodiments of the subject of the invention, which are schematically represented in the drawings.

The drawings show different embodiments, with complementary means for introducing the gas, for example through the side wall and / or bottom. In all these embodiments, as provided in accordance with the invention, the gas introducing means is also arranged in the mixing tools and / or the drive discs. However, this is not always explicitly represented in the drawings. Figure 1 shows a vertical section through a device according to a first example of an embodiment. Figure 2 shows a plan view of Figure 1, partially in section. Figure 3 shows, axonometrically, the construction of covers for the perforations. Figure 4 shows a further example of an embodiment, in vertical section. Figure 5 is a plan view of Figure 4, partly in section. Figure 6 shows, in detail, a vertical section through the drive disk. Figure 7 shows a vertical section through another example of an embodiment. Figure 8 shows a plan view thereof. Figure 9 shows a further example of an embodiment, in vertical section. Figure 10 shows a further example of an embodiment, in vertical section. Figure 11 shows a plan view thereof. Figure 12 shows a further example of an embodiment, in vertical section.

In the embodiment according to Figures 1 and 2, the device has a collecting vessel or a cutter-compactor 1 for the plastic material to be worked, especially thermoplastic, which is introduced into the collecting vessel 1 from above, for means of a loading device or conveyor belt, not shown. The introduced plastic material may be pre-crushed and / or dried. The collection container 1 is in the form of a cylindrical pot with vertical side walls 2 and has a horizontal flat bottom 3 with a circular perpendicular cut. The collection vessel 1 may be top closed or open. A shaft 4 passes through, sealingly installed, the bottom 3 and has a vertical axis 8, which corresponds to the axis of the container. The shaft 4 is driven, in a rotational movement, by a motor 5 with gears 6, installed below the bottom 3. In the collecting vessel 1 are fixed to the shaft 4, fixed with respect to rotation, a rotor 7 and a disk impeller 9 installed above it. The rotor 7 is constituted by a cylindrical circular block, the axial extent h of which is substantially larger than that of the impeller disc 9, but whose radial extent d is, however, essentially less than that of the impeller disc 9. In this way it is created under the impeller disc 9 is a free space 10 which is in free communication of current for the material to be worked with the space 26 of the collecting container 1, which lies above the impeller disc 9, through an annular slit 11 , which exists between the perimeter of the impeller disc 9 and the side wall 2 of the collecting vessel 1. Through this free annular gap 11 the plastic material to be worked arrives unimpeded into the annular space 10 from below, coming from the top space 26. The upper impeller disc 9 carries, on its upper side, a fixed upper mixing tool 21 which mixes and / or grinds and / or heats the material, which is located in the space 26 of the container. For effective grinding, the tool 21 can be constructed with cutting edges 22, which can be constructed curved or angled (Figure 2), counterclockwise relative to the direction of rotation of the drive disk 9 (Arrow 23) in order to efficient cutting.

In operation, rotation of the plastic mass introduced into the collecting vessel 1 takes place with the rotation of the impeller disc 9 by the influence of the tool 21, in which the material to be worked accumulates in height along the side wall 2 of the collecting container 1 in the space 26 (Arrow 24) and in the area of the container axis (Arrow 25) drops back. The mixing swirl thus created causes a whirlwind through the introduced material, so that a greater mixing effect is achieved. The material introduced into the collecting vessel 1 and, if necessary crushed therein, gradually arrives through the annular slit 11 into the space 10 below the impeller disc 9 and is treated therein by means of the mixing tools 12 situated closer to the surface of the bottom members 3 which are hingedly fixed to the rotor 7 by means of vertical pins 13 in annular grooves 14 of the rotor 7 so that these tools 12 can swing freely about the axes of the pins 13. The free ends of the lower tools 12 are spaced apart from the side wall 2 of the collecting vessel 1. These lower tools 12 perform a complementary mixing and / or comminution and / or heating of the material which is in the space 10 17

By centrifugal force exerted on the material by these lower tools 12, close to the bottom, the material is led to an outlet opening 15 of the collection container 1, which is more or less in height with the complementary lower tools 12 and alloys the space 10 of the collector vessel 1 to an inlet port 27 for the housing of a helical conveyor 16, in which a helical worm conveyor 17 is rotatably disposed and is driven through one of its top ends through of a motor 18 with gears 19 for the rotary movement and which compresses through its other end of the top the plastic material introduced therein, for example through an extrusion head 20. It can be a simple helical conveyer, of a double worm conveyor or of a multiple worm conveyor. As can be seen, the housing of the worm conveyor 16 is placed in a position more or less tangential to the container, so that returns of the plastified material are prevented through the helical worm conveyor 16, in the area of its output from the compartment 16. Instead the helical worm conveyor 17 may also be a helical conveying conveyor which carries the prepared material in the collecting vessel 1 for other uses, for example to an extruder.

In operation a state of equilibrium of weight between the material conveyed by the helical worm conveyor and the material which penetrates from above through the annular gap 11 into the space 10 is established after a short period of operation. This results in it being very unlikely that a particle of plastic material 18 introduced into the collecting vessel 1 will reach the housing of the helical worm conveyor 16 without sufficient residence time having been left in the collecting vessel 1 before. a sufficient treatment of all the particles of plastic material by means of the mixing tools 12, 21 so that the material supplied by the helical worm conveyor 17 exhibits approximately uniform properties, especially with respect to the temperature and the size of the particles of plastic material. This means that the plastification work provided by the worm conveyor 17 or by the extrusion helical conveying conveyor attached thereto is comparatively smaller, so that there are no requirements of high thermal tips for the plastic material in the plastification work . This saves the plastic material and essentially saves the drive energy to the worm conveyor 17 or the helical worm extrusion conveyor.

As mentioned, the material introduced into the collecting vessel 1 is generally not completely dry and / or has impurities, which in the treatment inside the container produce volatile substances, for example water vapor, products of decomposition of the treated material, vaporised cooling, volatile substances of coloring and / or printing etc. In order to effectively remove such unwanted substances or to prevent such volatile substances from accumulating in the space 10 below the upper impeller disc 9 and thereby prevent passage of the material to be treated out of the space 26 and into the space 10 and / or reaching the inside of the housing of the helical worm conveyor 16, the drive disc 9 according to Figure 1 and 2 has at least one, but nevertheless, and preferably several perforations 36, which join the space 26, above the drive disk 9, to the space 10 below it. Through these perforations 36 the volatile substances retained in the space 10 can pass through the impeller disc 9, dilating upwards and thus being led out of the collecting vessel 10, for example through a suction 51.

These perforations may consist of holes with a perpendicular cut of circular or slotted shape. At least some of these perforations 36 are placed near the axis 8 of the collecting vessel 1 and in fact immediately below the tool 21, so that the perforations 36, seen in the direction of rotation (arrow 23) of the impeller disc 9, are close to the edges 37 or rear edges of the tool 21. The suction action exerted by the tool 21, supported by the rotation of its rear edges, sustains upward aspiration of the volatile substances through the perforations 36.

The axes of the perforations 36 may lie vertically, however, it is convenient to position such shafts 38, according to Figure 6, not only obliquely with respect to the surface 39 of the impeller disc 9 but also with respect to the axis of the container 8. The inclination of the walls 40 of the perforations (Angle a, Figure 6) is conveniently between 30 and 60 °, preferably about 45 °. This inclination is chosen in such a way that the inlet end 41 of each of the perforations 36, seen in the direction of rotation of the pusher disk 9 (Arrow 23) lies ahead of the mackle end 42. This also supports the aforementioned suctioning action already opposes a direct fall of the material out of the space 26 through the perforations 36 into the space 10. It is still advantageous, as can be seen from Figure 3, to provide the perforations, or less some of them, with a cover 28, which covers the perforation 36 surrounding it, to an outer aperture 35 directed in the direction of the perimeter 43 of the drive disk 9 or radial (with respect to the axis 8). The size, i.e. the perpendicular cross-sectional surface of the perforations 36, depends on the amount of the fluid materials to be withdrawn. Generally, it is sufficient to construct the surfaces of the perpendicular cut of all the perforations 36, at most with measures as large as the perpendicular cut surface of all the worm helical conveyors or compartments of the helical conveyors, the extruder or the helical conveyor without end 17 which are in current connection with the outlet opening 15 of the collecting vessel 1.

In the lower region of the side wall 2 of the collecting vessel 1 there is installed or opens into the side wall 2 of the collecting vessel 1, means for introducing the gas 50 into the said collecting vessel 1. This means for introducing the gas 50 is constructed as an active means for introducing the gas 50 in the form of a nozzle, i.e. can blow gas under pressure into the cutter-compactor. The nozzle is at such a height or at such a distance from the bottom surface that it is continuously below the full predetermined filling state, according to the process, of the particles of material which are spin inside the compactor cutter 1, or the level of the mixing swirl formed by the movement or rotation of the material particles. The nozzle 50a is located in the lower third portion of the total height of the compactor cutter 1. The nozzle is disposed on the side wall 2 in the region between the upper mixing tools 21 or the impeller disc 9 and the lower mixing tools 12 or the lower impeller disc 29 and thus opens into the lower portion of the inner space 10. With more than two impeller discs or mixing tools installed one above the other, the gas introducing means advantageously delivers into the zone situated between the impeller disc located more above and the impeller disc situated downstream, or in the region situated between the mixing tools situated, respectively, upstream and downstream. In this way an advantageous downward flow and mixing can be ensured and therewith a favorable treatment of the material.

Advantageously, the means for introducing the gas 50 does not flow into the edge region of the impeller discs or the mixing tools, but rather, each of them in particular, opens or is placed in the zone between each two support discs or mixing tools, in the collecting vessel 1. The nozzle is constructed as a single opening in the side wall 2 and has a diameter of about 70 mm. In addition, there may be other openings at the same height, in particular distributed evenly along the periphery. The nozzle is provided with a cover 60, which prevents the rotating material from entering into the pressure into the nozzle. For this the cover is advantageously placed upstream with respect to the direction of rotation of the material, prior to the nozzle. The nozzle is essentially disposed on the opposite side of the outlet opening 15 of the collecting vessel 1. In the region above the material level there is provided a gas withdrawal means 51 in the form of an active gas suction or a fuel pump aspiration means 53. Alternatively the gas outlet means 51 may also be constructed as a passive gas withdrawal means, which is the case in a simpler embodiment, especially in the case of an overhead collecting vessel 1.

Through the nozzle is thus blown to the heated, dry air pressure into the collecting vessel 1. This air is conducted upwardly by the violent stream produced by the moving material and receives the moisture present or entrain the unwanted substances with it. By suction 51, the air enriched with the undesired substances leaves the collection vessel 1. Back is a residue of material almost free of unwanted substances. In this way, by means of the advantageous coordinated synergistic action of the gas passage 50, 51, of the two mixing tools 12, 21 and the perforations 36, it is possible to almost completely release the material from the undesired substances. The alternative embodiment according to Figures 4 and 5 differs from that according to Figures 1 and 2, in particular because the lower mixing tools 23 12 are not pendulously supported but rather are fixedly fixed to a further impeller disc 29 , which is coaxially installed with the impeller disc 9 and can be driven by the same shaft 4 in its rotational movement. In this way the rotor 7 may be of smaller construction or do not even exist as an extension of the shaft 4. As in the embodiment according to Figures 1 and 2, the downstream mixing tools 12 are placed at the height of the opening outlet 15 of the collecting vessel 1 so as to be able to efficiently conduct the treated plastic material present in the space 10 into the inlet opening 27 of the housing of the helical worm conveyor 16.

The other lower mixing tools 12, which are in the space 10, below the upper impeller disc 9, are fixedly attached to a further impeller disc 29 installed beneath the impeller disc 9, but may also be connected in a rigid manner hinged to the impeller disc 9, or pendant from the shaft 4.

As is already shown in Figures 1 and 2, a means for introducing the gas 50 is placed in the region between the support discs 9, 29 or between the upper and lower mixing tools 21, 12 and opens into the space 10. It is favorable that the temperature of the treated material inside the collecting vessel 1 is monitored. For this, as can be seen in Figure 4, a temperature measuring unit 30 and a cooling device 24 are provided in the upper cut-out space 26, above the pusher disk 9, the latter being constructed in the form of a nozzle for introducing the cooling medium.

As already mentioned, removal of the volatile unwanted substances penetrating the upper cut-out space 26 can be supported by a suction 51. To this end, a suction device 51 may be provided, as shown in Figure 4, mixing whirl which is formed in that cutting space 26.

In correspondence with Figure 4, a metering device 56 is installed in the gas path, which leaves the collecting vessel 1, with which the temperature of the outgoing gas and / or its humidity and / or the content in substances present in this gas.

There is shown schematically a control device 58, with which the device according to the invention or its unique elements can be controlled or regulated. In the present case the control device 58 is shown connected to the gas outlet means 51 and the gas introduction means 50. In the path of the introduced gas there is located a heating device 54 as well as a gas drying device 55 and a pumping or venting device 52. With these units it is possible, under the action of the control device 58, to regulate the volume, or the temperature, or the humidity of the introduced gas. It is also possible to use the temperature or the humidity of the gas leaving to regulate the temperature and / or the volume and / or pressure of the introduced gas. 25

As long as the collecting vessel 1 is constructed as a closed vessel, the amount of gas introduced through the inlet 50 corresponds essentially to the amount of gas exiting through the gas outlet 51. The leaving gas may have separation units for the for example cyclones or gas separators and can be reintroduced as a purified gas, always recycled, into the gas introduction opening 50. The device of Figures 7 and 8 is similar to the embodiment shown in Figures 1 and 2 , but however no perforations 36 are constructed in the upper impeller disc 9. As regards its shape, reference is made to the above embodiments.

Also in the present embodiment, a free internal space part 10 is formed below the upper impeller disc 9, which is in current-free connection to the material treated with the upper free inner space 26 of the collecting vessel 1, the middle of the annular gap 11 created between the outer perimeter of the impeller disc 9 and the side wall 2 of the collecting vessel 1. By means of this annular slit 11 the treated plastic material can thus pass unhindered from the space 26, situated above the impeller disc 9 , to reach the part of the annular inner space 10 located below it.

In this annular space 10 lower mixing tools 12 are installed, which run in this annular space around the axis 8. By means of the centrifugal force exerted by these mixing tools 12 on the plastic material, the plastic material is pressed into an outlet opening 15 of the collection container 1, the opening 15 which is located at the height of the tools 12 and which connects the inner space part 10 of the collecting vessel 1 into a cylindrical compartment 16, in which an endless helical conveyor 17 is rotatably installed. The upper impeller disc 9 is also provided with upper mixing tools 21, which are nevertheless fixedly attached to the impeller disc 9. These upper mixing tools 21 mix and / or grind and / or heat the material which is in the inner space part upper portion 26 of the collector vessel 1. For effective grinding it is favorable for the tools 21 to be constructed with sharp edges 22.

When in movement, a rotation of the mass of plastic introduced into the collecting vessel 1, with which the plastic material rises (Arrow 24), in the inner space part top 26, along the side wall 2 of the collecting vessel 1 and in the area of the axis of the collecting vessel 1 it moves back downwards (arrow 25). The resulting whirlwind entrainment entrains the introduced material so that a better blend is obtained. A reduced portion of the material introduced into the already crushed collecting vessel 1, however, arrives through the annular slit 11 into the lower inner space 10 below the upper impeller disc 9 and is therein treated by the lower mixing tools 12. Past a short working time establishes a state of equilibrium between the material driven by the helical worm conveyor 17 to 27 outside the outlet opening 15 and therefore out of the annular space 10 and the material passing from above through the annular gap 11 to the circular space 10. This has the consequence that it is very unlikely or even impossible for a particle of plastic material, once introduced into the collecting vessel 1, to reach the housing of the helical worm conveyor 16, without having previously had a sufficient residence time in the collecting vessel 1 or without having been sufficiently treated by means of the tools 12, 2 1. The quantities of plastic material passing through the outlet opening 15, which are driven by the helical worm conveyor 17, therefore have more or less uniform properties, especially with respect to the temperature and particle size of the material plastic. The worm conveyor 17 does not therefore need to apply much work to the mass of plastic material to bring the mass of plastic material to the desired degree of plasticity, which results in the absence of high thermal requirements in the helical conveyor 16, which act on the plastic material. In this way the plastic material is spared and the energy for the drive of the helical worm conveyor 17 is essentially spared. The shape and size of the annular space 10 are governed in view of the field of application. The distance h, at which the lower side of the impeller disc 9 lies from the bottom 3 of the collecting vessel 1, depends on the height of the rotor 7 and also on the size and position of the outlet opening 15. Favorable characteristics are obtained when the height h of the annular space 10 is at least equal, preferably substantially larger, than the diameter d of the helical worm conveyor 17 or 28 than the inner diameter of the housing of the helical worm conveyor 16. In the exemplary embodiment shown in Figure 7 is h: d = 1.56 and a favorable arrangement has been found wherein the part of the annular space 10 covered by the impeller disc 9, external to the rotor 7, has an approximately quadrangular perpendicular cut. Further forms of perpendicular cutting of this annular space are possible, especially when other tools work in this annular space 10, for example a rotor 7 constructed as a blade wheel.

As can be seen, the size of the annular slit 11 influences the described manner of operation. This annular gap should not be too large in order to prevent larger material particles from being introduced through this annular slit. On the other hand, this notch must also not be too small, since very little material will therefore reach the inner part of the lower space 10 located below the impeller disc 9 and in this way the danger of the helical worm conveyor 17 being not sufficiently completed. In order to be able to adapt to different materials to be treated, the size of the annular slit 11 may be of variable construction, for example by movable building parts, applicable to the drive disk 9, by means of which the slit 11 may be partly covered or release at a greater width. Such construction parts may possibly be provided on the wall 2 of the collecting vessel 1. Assays have shown that favorable values for the width measured in the radial direction s (Figure 7) of the annular slit 11 are in the region of 20 to 150 mm, preferably 20 to 100 mm, regardless of the diameter of the collecting vessel 1, but depending on the type of product to be treated. It is desirable that the tools 12 lying within the lower inner space 10 of the collection vessel 1 are shaped such that the plastic material therein is treated less intensively than the one dragged by the tools 21, the drive disk 9 in the upper inner space portion 26 of the collecting vessel 1.

Also in this embodiment there is provided means for introducing the gas 50 into the zone between the drive discs 9, 29 or between the upper and lower mixing tools 21, 12, which opens into the space 10. Figure 9 shows, in vertical section, a further embodiment. This device has a collecting container 1, in which only a single impeller disc 9, 29 is provided with mixing tools 12, 21 in the lower zone adjacent the bottom 3, at the height of the outlet opening 15. These mixing tools 12, 21 produce a movement of the particles of material or a mixing swirl 25.

On the bottom 3 and in particular on the innermost third of the bottom surface 3 there is provided an active means for introducing the gas 50, in the form of an annular slit around the shaft 4, especially if almost piercing, through which gas, impelled by a fan 52 is introduced. In addition, there is constructed, in the side wall 2 of the collecting vessel 1 and in effect at the height in which, by means of the particles of moving material, the greatest pressure is exerted on the side wall 2, another active means for introducing the gas 50 , which is also constructed as a peripheral crevice, which extends to almost the entire periphery. Through both the gas introduction means 50, gas is blown into the collecting vessel 1, which passes through the material and is expelled, enriched with the undesired substances, through the gas withdrawal means 51.

Figures 10 and 11 show, in vertical section and in plane, another example of an embodiment. The device, which is only partly shown in Figures 10 and 11 - therefore only the lowermost impeller disc 29 or the lowermost mixing tools - are represented, in the features not shown, to the devices shown in Figures 1 to 9. It does reference is therefore made, with respect to the features not shown, to these Figures 1 to 9.

On the lower side of the lowermost drive disk 29 are several drive blades 65. These drive blades 65 start from the center of the drive disc 29, radially bent and against the direction of rotation and extend over the entire disc radius The impeller blades 65 are constructed as bar-like cores and protrude into the zone between the impeller disc 29 and the bottom surface 3.

The impeller blades 65 produce, when in operation, a flow of material, acting in such a way that no treated material remains in this region, located below the impeller disc 29. The material to be treated is forced by the impeller blades 65 to pass through from the annular slit 11 upwardly to the region above the impeller disc 29. When perforations 36 are constructed in the impeller disc 29, the material can then also penetrate through these perforations 36.

On the surface of the bottom 3 of the collecting vessel 1, gas introducing means 50 are constructed near the central axis 8, which flow into the region below the impeller disc 29. The gas introduction means 50 can be constructed as active or passive gas introduction means. In this way the gas or air can be actively drawn into the zone below the impeller disc 29 or sucked through the impeller blades 65. The gas then runs upwards, as shown in Figure 10 by the arrow 68, through the annular gap 11 and thereby supports the outlet of the material to be treated out of the zone below the impeller disc 29. The gas also runs through the perforations 36, whenever constructed, as shown in Figure 10 by means of the arrow 69 and thereby drives up the material.

In this embodiment the impeller blades 65 therefore advantageously act in concert with the gas introducing means 50 and optionally with the perforations and thereby ensure an efficient transfer of the material out of the area situated below the impeller disc 29 .

Such impeller blades 65 or a combined arrangement of such impeller blades 65, perforations 36 and / or gas introducing means 32, 50 may be constructed in all of the devices shown in Figures 1 to 9.

A further advantageous embodiment is shown in Figure 12. This is of analogous construction to the embodiment according to Figures 4 and 5. Reference is therefore made to the embodiments of Figures 4 and 5. As different from Figures 4 and 5, the gas introduction means 50 are, however, constructed on the bottom surface 3, as is also the case in the embodiments of Figures 9, 10 or 11.

In all of these embodiments of Figures 1 to 12, the gas introduction means are also, as provided in accordance with the invention, installed in the mixing tools and / or the impeller disks, even when such gas introduction means is not provided. are explicitly represented.

According to an advantageous embodiment of the process, it may be provided that the gas is introduced through gas introduction means 50 constructed in at least one mixing tool 12, 21, particularly in the mixing tool 12 closest to the bottom, preferably on the downwardly facing side or to the bottom surface 3 of each of the mixing tools 12, 21, preferably pressure activated or through active means for introducing the gas 50 into the collecting vessel 1.

According to an advantageous device it can be provided that the gas introducing means 50 is constructed in at least one mixing tool 12, 21 or at least one impeller disc 9, 29, especially in the lower mixing tool 12 or the lower impeller disc 29, placed closer to the surface of the bottom 3, preferably on the underside or side of each of the mixing tools 12, 21 or each of the drive discs 9, 29, facing the surface of the bottom 3, in this case, the gas introducing means 50 is preferably constructed as the active means for introducing the gas 50a.

According to a further alternative device, it may be provided that the means for introducing the gas 50 are installed near the axis 8 and especially near the edges 37, rearward relative to the direction of rotation of the drive disc 9, of the tool 21, or near of the piercing aperture 36.

According to an advantageous embodiment of the process, it may further be provided that the gas is introduced into the collecting vessel 1 through a gas introducing means 50 constructed on the bottom surface 3 of the collecting vessel 1, below the closest mixing tool 12 of the surface of the bottom 3, preferably in the inner third of the radius of the surface of the bottom 3.

According to an advantageous embodiment, it may be further provided that the gas is introduced into the collecting vessel 1 by means of introducing the gas 50, preferably activated by pressure or by active means of introducing the gas 50, constructed in a side wall 2 of the collecting container 1, particularly in the area of the lower third of the height of the collecting vessel 1 and / or in the area below the mixing tool 12 placed below, closer to the bottom. 34

According to an advantageous embodiment of the process it may be provided that the gas in the presence of two or more overlapping mixing tools 12, 21 is introduced into the zone between the mixing tools 12, 21.

According to an advantageous embodiment of the process it may be further provided that the gas is introduced through any zone of the collecting vessel 1, wherein the particles of material moving or rotating within the collecting vessel 1 exert the greatest pressure on the side wall 2 of the collecting vessel 1.

According to an advantageous device it may be further provided that the gas introduction means 50 has, on its side facing the inside of the collecting vessel 1, particularly above the direction of rotation of the material contained in the collecting vessel 1, a cover or a guard 60 to protect them from the material in the collection container 1.

According to another advantageous device, it may be provided that the gas introducing means 50, are constructed on the bottom surface 3 of the collecting vessel 1, below the lower tool 12, closer to the bottom, preferably within the third inner ray of the bottom surface 3.

According to an advantageous device, it may in addition be provided that the gas introduction means 50 is constructed in the form of a circular slit 35, which runs around the passage of the drive shaft 4, through the surface of the bottom 3.

According to an advantageous device it may be further provided that the gas introduction means 50 are placed in the side wall 2 of the collecting vessel 1 or are discharged or are constructed in the side wall 2 of the collecting vessel 1, wherein the gas introduction means 50, in this case preferably being constructed as active means for introducing the gas 50.

According to an advantageous device it may be further provided that the gas introduction means 50 are placed in the collecting vessel 1 at a certain height or at a certain distance from the surface of the bottom 3, in which the means for introducing the gas 50 are situated permanently below the total filling state of the collecting vessel 1, predetermined according to the process for the particles of material, which are or are rotated in the collecting vessel 1, or of the level of the mixing trunk constituted by the rotation of the particles of material, in that the gas introducing means 50 is particularly placed in the lower third of the height of the collecting vessel 1, preferably below the lower mixing tool 12, closer to the bottom.

According to an advantageous device it may be further provided that the gas introducing means 50 are placed in the side wall 2, in the region between the at least two impeller disks 9, 29 or mixing tools 12, 21, installed one on top of the other, or in the region between the impeller disks or mixing tools placed higher up and down, preferably between the upper mixing tool 21 or the upper impeller disc 9 and the lower or downstream mixing tool 12 or the lower or situated impeller disc 29 or lower into the lower portion of the inner space 10, wherein the insertion means 50 is preferably each preferably located in the region between each two impeller discs or two mixing tools or, in particular, the space between them or in the space between them.

According to an advantageous device it may be further provided that the gas introduction means is installed in each of the zones of the side wall 2 of the collecting vessel 1, on which particles of moving material or rotation in the collecting vessel 1 exert the pressure on the side wall 2 of the collecting vessel 1.

According to an advantageous device it may be further provided that the gas introducing means 50 is placed in the side wall 2, at the same height along the entire perimeter of the inner wall of the collecting vessel 1, preferably uniformly spaced apart.

According to an advantageous device it may be further provided that the gas introduction means 50 are formed in the side wall 2 in the form of a peripheral annular slit, in particular a total peripheral slot.

Lisbon, July 27, 2012

Claims (15)

Process for the preparation of a material, in the form of fragments or particles, particularly and preferably in the form of polymeric particles or thermoplastic flakes or the like, present in a collecting vessel or cutter-compactor (1), moved or placed in (12, 21) in which, following the process, undesirable pernicious substances, which hinder the preparation or the subsequent treatment of the material, for example volatile substances, in particular moisture or water vapor are withdrawn from the material when a gas, particularly air or an inert gas, is introduced into an area below the service level of the material in the collecting vessel (1), or below the level of the material of the mixing swirl formed within the collecting vessel (1), wherein the gas is passed through a partial region l of the material by means of the formation of a forced stream and then the gas, now enriched or saturated with undesired substances, is sent out of the collecting vessel (1), in an area above the service level of the material being (1) or above the level of the material contained in the mixing swirl, characterized in that the gas is introduced into the collecting vessel (1) by means of introducing the gas (50), which are constructed or installed in at least one mixing tool (12, 21) and / or in a drive disk (9, 29) supporting the mixing tool (12, 21). 2 A process according to Claim 1, characterized in that the gas is introduced through the gas introducing means (50) constructed in the mixing tool (12) closest to the bottom and / or in the proximal impeller disc (9, 28) from the bottom. A process according to Claim 1 or 2, characterized in that the gas is introduced through gas introduction means (50) constructed on the underside or side facing the bottom surface (3) of each mixing tool (12). , 21) and / or the impeller disc (9, 29) closest to the bottom. Process according to one of Claims 1 to 3, characterized in that the gas is introduced through at least one active gas introducing means (50), for example through nozzles or blowing openings, which can be operated by means of pumping means or (52) in which, driven or blown, it is activated by the pressure in the collecting vessel (1) below the material level and / or in that the gas is sucked or pumped through at least one active withdrawal means (1) above the level of the material and / or the gas is heated and / or dried prior to introduction and / or by the gas exiting from the collecting vessel (1) ), the temperature, humidity and / or the content of unwanted substances are measured, and the volume, temperature and / or humidity control of the gas entering the collecting vessel (1) depends on these measured values. A device for carrying out the method according to one of Claims 1 to 4, with at least one collecting container or cutter (1), in the form of a funnel or cylindrical, having a bottom surface (3) and a side wall (2) in which at least one mixing tool (12, 21) is provided, optionally installed on a drive disk (9, 29), which is rotatably movable about a vertical axis (8 ), wherein the mixing tool (12, 21) and the impeller disc (9, 29) are disposed above the bottom surface (3) and spaced apart therefrom, wherein the mixing tool (12, 21) mixing, heating or optionally crushing or acting on a material to be treated, preferably in the form of pieces or particles of polymeric materials, particularly in the form of unfused polymeric particles, present inside the collecting vessel (1), wherein, in the collecting vessel (1), is or, below the level of the material of a mixing swirl formed during operation, at least one gas introducing means (50), for introducing a gas, in particular air or an inert gas, into the interior of the vessel. (1) and wherein in the collecting vessel (1), above the level of the material which is inside the collecting vessel (D during operation or above the level of the mixing swirl material, at least one medium (51) for the exit of the enriched or saturated gas from unwanted substances, in particular water vapor, from the collecting vessel (1), characterized in that the gas introduction means (50) is constructed and / or placed in the or on the mixing tool (12, 21) and / or being constructed in or on the impeller disc (9, 29). 4 Device according to Claim 5, characterized in that the gas introducing means (50) is constructed or placed on the lower mixing tool (12) closest to the bottom surface (3) and / or the lower impeller disc (29). Device according to Claim 5 or 6, characterized in that the gas introducing means (50) is constructed or placed on the underside or side facing the bottom surface (3) of each of the mixing tools ( 12, 21) and / or each of the drive discs (9, 29). Apparatus according to one of Claims 5 to 7, characterized in that at least one helical conveyer (17) is provided for withdrawing the material from the collecting vessel (1), the compartment (16) is connected, for example radially or tangentially, to an outlet opening (15) of the collecting vessel (D) by means of an inlet opening (21), wherein the outlet opening (15) is situated in the side wall 2) near the bottom surface (3) of the collecting vessel (1). Device according to one of Claims 5 to 8, characterized in that each of the mixing tools (12, 21) is placed on a drive disk (9, 29), which is driven by a shaft (4) inserted in the space (1) in order to rotate about the axis (8) of the shaft (4). A device according to one of Claims 5 to 9, characterized in that at least two mixing tools (12, 21) are placed on top of one another in the collecting vessel (1) in particular and precisely installed on a drive disc (9), particularly with the upper mixing tool (21) installed on a lower impeller disc (29), closer to the bottom, the lower mixing tool (12) or closer to the bottom (3), wherein, in the container (1), above the upper mixing tool (21), an upper part of internal space (26) is formed, as well as, below the upper mixing tool (21), in the same collecting vessel (1). a lower inner space portion 10, in which the mixing tool 12 closest to the bottom and the mackerel aperture 15 are disposed, wherein the upper inner space portion 26 is in communication with the part of the internal space (10) of the collecting vessel (1), in particular through a free annular gap (11) between the outer perimeter of the upper impeller disc (9) and the side wall (2) of the collecting vessel (1), whereby , with the rotation of the upper mixing tool 21, a part of the material which is in the upper inner space 26 passes, particularly through the annular groove 11, to the lower inner space 10 and hence, through the lower mixing tool 12 closer to the bottom, is drawn into the outlet opening 15. Device according to one of Claims 5 to 10, characterized in that the upper impeller disc (9) has at least one perforation (36), preferably installed close to the axis (8) and particularly close to the rear edges (37) of the tool 21, which traverses the drive disk 9 and joins the upper inner space 26 to the lower inner space 10. Device according to one of Claims 5 to 11, characterized in that the means for introducing the gas (50) are placed near the axis (8) and especially close to the rear edges (37) with respect to the rotation of the impeller disc (9). ) of the tool (21) or near the perforation (36). Device according to one of Claims 5 to 12, characterized in that the gas introducing means (50) is constructed as passive means for introducing the gas (50), for example as passage openings, through which the gas can is passively sucked into the collecting vessel 1, due to the depression in the collecting vessel 1 or the gas introduction means 50 can be constituted as active means for introducing the gas 50, such as for example nozzles or the like operated by means of pumping or blowing devices (52), through which the gas can be pumped, piped or blown into the collecting vessel (1) by means of active pressure and / or the withdrawal means (51) are constructed as passive gas withdrawal means (51), for example in the form of through openings, through which gas can be withdrawn passively, for example through the overpressure in the recipient and collector (1) out of the collecting vessel (1) or the gas withdrawal means (51) can be constructed as active, actionable, for example, by means of suction devices (53), through which the gas can be actively sucked or pumped out of the collecting vessel 1 and / or in that a heating device 54 is connected before the gas introduction means 50, through which the gas to be introduced into the interior of the collecting vessel 1 may be heated and / or in that a gas drying device 55 connected before the gas introduction means 50 is provided, through which the gas to be introduced into the collecting vessel ( 1) is dry and / or in that the gas introduction means (50) for regulating the gas introduction and / or withdrawal of the gas are at least partially lockable or controllable and / or the gas introduction means (50) are constructed as single, single openings with a preferably between 50 and 90 mm and / or in that the gas introducing means (50) is completely melted with the inner wall of the mixing tool (12, 21) and in particular not protruding from inner side of the mixing tool (12, 21) into the container (1). Device according to one of Claims 5 to 13, characterized in that on the lower side of a drive disc (29) situated lower down and facing the bottom surface (3) and optionally also the lower side in all other the drive discs (9), at least one, preferably a plurality of drive blades (65) are constructed, which protrude from the drive disc (29), in particular in the radial direction and possibly of arcuate construction, which actuate a drive chain gas and material from the area situated below the lowermost drive disk 29, 8 upwards, particularly through the annular groove 11 and / or the perforations 36, to the region situated above the located drive disc further below (29). Device according to one of Claims 5 to 14, characterized in that the gas withdrawal means (51) is disposed on one of the bottom surfaces (3) of the collection vessel (1) or in areas remote from the material or the swirl (1) and / or in that at least one measuring device (56) is provided, in particular placed after the gas withdrawal means (51), which is reached by the outgoing gas, in order to measuring the temperature and / or possibly the humidity or the content of undesirable substances in the gas leaving the gas withdrawal means (51) from the collecting vessel (1) and / or in that a control device (58) is provided, , that some of the following devices, such as the heating device (54) and / or the drying device (55) and / or the pumping or blowing device (52) and / or the suction device (53) are present, , to which it is linked, controls or regulates them, dependence of predetermined material parameters and / or the temperature of the leaving gas and / or the type of the undesired materials. Lisbon, July 27, 2012